Dapsone is now recommended therapy for both prophylaxis and treatment of pneumocystis carinii pneumonia in children with HIV infection who are unable to tolerate trimethoprim/sulfamethoxazole. While data are available describing Dapsone pharmacokinetics in adults, no data are available for children. This protocol is designed to delineate basic pharmacokinetic parameters of Dapsone in HIV infected children following oral dosing.